First and foremost at No. 4 is Gehrig. Famous and fabulous and hardly fictitious. (You know preteen Don Mattingly believed Babe Ruth was a cartoon character. But of course, the Babe was the 3 to Gehrig's 4, the powerful yin to Gehrig's extraordinary yang.)

Gehrig remains as recognized for being No. 4 as Neil Armstrong is for being No. 1. Decades after his death, he is as readily related to his integer as Dalmatians are to 101 and Wilt Chamberlain in to 100.

No. 4 and the Yankees' forever first baseman -- all due respect to Mattingly as well -- form a wonderful union of name and number within the game, like the '69 Mets or '04 Red Sox. One prompts recall of the other. The image is as strong as Gehrig in his heyday. Little explanation is needed.

That Gehrig is a Hall of Famer requires zero explanation to even the casual fan. What may demand clarification is why one the most elite players in the long history of the game is about to be inducted into the Hall on Sunday, 74 years after his plaque took its place on a wall in baseball's Smithsonian.

Gehrig was voted into the Hall in a special election at the Winter Meetings in Cincinnati on Dec. 7, 1939, some seven months after his final game, 5 1/2 months after his retirement and diagnosis of the debilitating disease that took his life and later his name. His induction -- sans ceremony -- was immediate.

Chances are, he would have been unable to attend Cooperstown ceremonies in the summer of 1940 because of the weakness that had crippled his once-strapping body. Film footage shot at Lou Gehrig Appreciation Day, July 4, 1939, illustrates a stunning loss of strength. Merely 65 days after his final game, he was unable to hold some of the gifts presented him at the ceremonies at Yankee Stadium.

Indeed, on the morning of the afternoon salute, doubt developed that the erstwhile Yankees captain would be physically able to deliver his famous speech, the proclamation that he was the "luckiest man on earth" even as his body was ravaged by the symptoms of amyotrophic lateral sclerosis, a rare disorder that gradually but completely eliminates muscle function.

But the man who had a healthy disdain for days off persevered that summer day and created an iconic moment the nation has embraced ever since.

"You grew up, knowing all about that," Yankees manager Joe Girardi said at the Yankees' Old-Timers' Day in 2011. "But the older you get, the more you understand what it means and how he lived his life."

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Because of the special -- and tragic -- circumstances, the Class of '39, the Hall's fourth class, acquired a valedictorian and its 10th member months after its enshrinement. Cap Anson, Eddie Collins, Buck Ewing, Wee Willie Keeler, Old Hoss Radbourn and George Sisler were ceremoniously enshrined as players; Charlie Comiskey, Candy Cummings and Al Spalding as baseball pioneers/executives.

And now Gehrig, the great Rogers Hornsby and the 10 members of the Class of 1945, each of whom was denied the experience of an enshrinement ceremony, are to form posthumously a class of a different sort. They are to be inducted properly, formally ... finally.

The Iron Horse is to be saluted Sunday by, among others, the former player who brought him back to life via the celebrated pursuit of the record for consecutive game played Gehrig had established from June 1, 1925, to April 30, 1939. Cal Ripken passed and displaced Gehrig on Sept. 6, 1995, and now, nearly 18 years later, he is to read the words from Gehrig's plaque. It is a fitting connection, as is Joe Morgan's reading Hornsby's plaque -- one special second baseman saluting another.

The weekend will be quite unusual because of that new wrinkle and because no player on the 2012 ballot was elected in the winter vote of the Baseball Writers' Association of America announced in January. The Hall had anticipated that development and planned to stage formal ceremonies for Gehrig, Hornsby and the others to fill the void and to make Sunday's event worth attending.

The Hall could have done worse than to have Gehrig and Hornsby to camouflage the lack of new inductees. Each is all but guaranteed to be in any conversation of the 10 greatest position players, Gehrig for his performance, steadfastness and courage; Hornsby for his extraordinary production as a precision batsman.

Hornsby, who, incidentally, wore No. 4 (for the Cardinals in 1933 and the St. Louis Browns in 1936 and '37), is often identified as the greatest right-handed hitter in the National League and quite comparable to Ty Cobb. His career average of .358 in 23 seasons is eight points lower than the all-time high produced over 24 American League seasons by Cobb's left-handed swing.

Hornsby could be elected to the Irascible Hall of Fame as well. He was the polar opposite of Gehrig, who was revered and beloved. Gehrig's image was enhanced by his vulnerability and the unsettling nature of his final years. That he played for the Yankees at a time of franchise greatness, that he was their first captain and that he was the cleanup hitter in Murderers' Row also reinforced the image. And Gary Cooper's portrayal of the Iron Horse in "Pride of the Yankees," opposite lovely Teresa Wright on the silver screen, while a tad sanitized, also warmed America's heart.

Hornsby was an all-star introvert, a man not easily or widely liked. Teammates avoided him when he was present -- which was not as often as it might have been. He was quick to shower -- if he showered at all -- and flee the clubhouse. When he managed, he sometimes departed before game's end. In the newspapers, he was Rajah, an identity that conveyed his stature as royalty. In the clubhouse, he could have been the Iron Fist -- unyielding and stoic.

"He didn't have that many friends," Hall of Famer Billy Williams said Friday. "He was a tough guy to know. Very direct. Awfully blunt. He made people uncomfortable."

Williams recalled the late '50s, when he and fellow Hall of Famer Ron Santo were in the Cubs' Minor League system and Hornsby was in the club's employ as an organizational hitting coach. Then-Cubs general manager John Holland had Hornsby evaluate the talent outside the big league team. After Hornsby had delivered face-to-face indictments to several player -- "You can't play," and "Son, you better find a job 'cause you'll never hit in the big leagues" -- he reported his observations to Holland: "Williams can hit in the big leagues right now" and "Santo will help you win baseball games very soon."

Then he added this conclusion: "Release the rest of 'em."

What Hornsby lacked in tact and personality was always overlooked or forgiven because he could hit. Oh, could he hit! We marvel at the .406 batting average Ted Williams produced in 1941. Hornsby batted .402 from 1921 through 1925. His statistical resumé that appears on websites is seemingly margin-to-margin bold-faced numbers. He led the National League in batting as well as on-base and slugging percentages from 1920-25, and he averaged 216 hits, 115 RBIs and 118 runs. He won the Triple Crown twice in those six seasons.

"He stood way back in the batter's box, and most of his hits went to right-center field," Kiner said Wednesday.

The Hall of Fame slugger recalled the 1962 season, when Hornsby served as the batting coach for the first-year Mets. "I got along with him," Kiner said. "I guess he liked me, but I could see why people said what they said about him. He was irascible, and a loner most of the time."

And Kiner also remembered Hornsby taking batting practice that year, at age 66, and spraying line drives around the Polo Grounds and other National League parks.

"The greatest right-handed hitter?" Kiner said. "Doesn't it have to be him? Who else did what he did?"

Gehrig's resumé was different but also dazzling. Twenty-three grand slams, 1,992 RBIs, the fifth most ever, produced in a shortened career, a Triple Crown. Batting behind a man who often cleared the bases, Gehrig led the American League in RBIs four times from 1927-31, establishing the league record of 184 in '31. He averaged 141 runs and 150 RBIs over 12 seasons (1926-37).

And he played in 2,130 consecutive games, an accomplishment that for decades was characterized as an unbreakable record.

Well...

Another left-handed-hitting first baseman from New York, an astute observer of hitting technique, recently saw footage of Gehrig taking batting practice at Yankee Stadium in the '30s. And Keith Hernandez gushed about what he had seen. He recalled Barry Bonds taking batting practice during his tour with the Giants. Bonds had the BP pitcher move 20 feet in from the mound and throw harder than most BP pitchers would.

"When he took his last turn," Hernandez said. "Barry'd lean back, angle his body back and square up his shoulders. He was working on his bat speed. When I saw the video of Gehrig, it reminded me of Barry. Gehrig was so muscled. God! When you saw his mechanics -- he did everything right -- and that body. He was just a horse," though with no mention of Iron. "When you saw that swing, you thought 'No wonder he had those kind of numbers.' What he did looked perfect."

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So it was for the man called Buster and Larrupin' Lou and -- for reasons that are not as clear as they might be -- Biscuit Pants. Ruth was enjoyed, Joe DiMaggio was revered, Mickey Mantle was beloved. Gehrig was all of the above.

What better way to recognize him -- other than induction -- than to present some significant baseball 4's in his honor?

We know full well why No. 4 was assigned to Gehrig; he was the cleanup man in the batting order manager Miller Huggins maintained throughout the signature season of that generation of Yankees. The Iron Horse was the protection for the Babe. "Like protecting the Pyramids with the Wall of China," historian Reggie Jackson once suggested.

The order was routinely identical: Earle Combs, Mark Koenig, then Ruth third and Gehrig fourth, always in that sequence like Crosby, Stills, Nash and Young.

(Gehrig had more hits, they had more albums.)

He also had more 4's than a memorabilia convention pushing the uniforms of Jackson, Jerry West, Willie McCovey and Hank Aaron. A sampling follows:

Gehrig's 4 was the first uniform number retired in professional sports. No. 4 has been retired eight times, for Gehrig, Kiner, Ott, Snider, Weaver, Molitor, Joe Cronin and Luke Appling. Gehrig led the league in runs four times, led in on-base average four straight seasons (1934-1937), hit four home runs in the four-game World Series in 1928 and was the first player to hit four home runs in one game in the 20th century -- June 3, 1932. He nearly hit a fifth.

So now, borrowing the sound that, for decades, has greeted men in the game named Brock, Piniella, Whitaker and Merloni, let us salute the great first baseman of the Yankees, the man who would not sit and who delivered a speech that still resonates with us, 74 years after it was spoken.

Marty Noble is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.